TITLE 77: PUBLIC HEALTH
CHAPTER I: DEPARTMENT OF PUBLIC HEALTHSUBCHAPTER r: WATER AND SEWAGE
PART 890
ILLINOIS PLUMBING CODE
SECTION 890.1230 SAFETY DEVICES

Section 890.1230 Safety
Devices

a) All equipment used for heating water or storing hot water
shall be provided, at the time of installation of the equipment, with the
required relief valve or valves to protect against excessive or unsafe
temperature and pressure. This shall be achieved by installing either a
pressure relief valve and a temperature relief valve or by installing a
combination pressure-temperature relief valve.

b) Pressure and Temperature Relief Valves

1) Pressure Relief Valves. Pressure relief valves shall have an
ASME relief rating to meet the pressure conditions specified on the equipment
served. They shall be installed in the cold water supply line to the heating
equipment served, except where scale formation from hard water may be
encountered, in which case they shall be installed in the hot water supply line
from the heating equipment served. There shall not be a shut-off valve between
the pressure relief valve and the tank. Except when an alternate design is
approved by the Department in writing pursuant to Section 890.140(a)(2) or
890.1940, the pressure relief valve shall be set to open at a maximum of the
working pressure rating of the water heater, but shall not exceed 150 psi. Each
pressure relief valve shall have a test lever.

2) Temperature Relief Valves. Temperature relief valves shall
bear the Canadian Standard Association (CSA) relief rating, expressed in
British Thermal Units (BTU) of heat input per hour, for the equipment served.
They shall be installed so that the temperature-sensing element is immersed in
the hottest water within the top 6 inches of the tank. The valve shall be set
to open full when the stored water temperature is 210 degrees Fahrenheit.

c) Combination Pressure-Temperature Relief Valves

1) Combination pressure-temperature relief valves shall comply
with the applicable requirements listed in Appendix A.Table A (Approved
Standards for Plumbing Appliances/Appurtenances/Devices) for individual
pressure and individual temperature relief valves, shall be installed so that
the temperature sensing element is immersed in the hottest water within the top
6 inches of the tank, and shall have a test lever.

2) A check valve or shut-off valve shall not be installed between
any safety device and the hot water equipment, nor shall there be any shut-off
valve in the discharge pipe from the relief valve. (See Appendix I.Illustrations
N and O.)

3) Energy cut-off devices shall not be used in lieu of
subsections (c)(1) and (2) and shall be of a design to properly serve the
intended use of the plumbing appliance, appurtenance or device. Exception:
Instantaneous cut-off devices are exempted or may be used.

d) Relief Discharge Outlet

1) A relief discharge outlet shall be installed and be indirectly
connected to waste. The discharge pipe from the relief valve shall not be
located so as to create a safety hazard or to discharge so as to cause damage
to the building or its contents. The relief valve shall not discharge through
a wall into the outside atmosphere or where there is a possibility of freezing.

2) No reduced coupling, valve or any other restriction that would
impede the flow of discharge shall be installed in the discharge line of any
relief valve. The discharge line shall be installed from the relief valve to
within 6 inches of the floor or receptor and the end of the line shall not be
threaded.

3) Any piping used for discharge from the relief valve shall be
of metallic material, shall comply with Appendix A. Table A (Approved Materials
for Water Distribution Pipe) for potable water piping, and shall drain
continuously downward to the outlet.

4) The discharge piping shall discharge indirectly into a floor
drain, hub drain, service sink, sump or a trapped and vented P-trap that is
located in the same room as the water heater. (See Sections 890.1010 and
890.1050(a), (b) and (c).) The trap shall have a deep seal to protect against
evaporation or shall be fed by means of a priming device designed and installed
for that purpose. The use of a light grade oil in the trap will retard
evaporation.

e) Pressure Marking – Hot Water Storage Tank. Hot water storage
tanks shall be permanently marked in an accessible place with the maximum
allowable working pressure.

f) Vacuum Relief Valve. If a hot water storage tank or water
heater is located at an elevation above the fixture outlets in the hot water
system, or if the storage tank or water heater is bottom fed, a vacuum relief
valve as listed in Appendix A.Table A (Approved Standards for Plumbing Appliances/Appurtenances/Devices)
shall be installed on the storage tank or heater.

g) Multiple Temperature Hot Water Systems. These systems shall
be provided with thermostatic mixing valves to control the desired
temperatures.